My regular RP partner and I treat in-game death and rez as "Badly wounded" and "Takes time/resources to recover with a possible chance of permanent injury."
Honestly I always thought LoTRO handled it best. Health = Morale and you aren't killed, you're too beaten or tired to continue and withdraw from the fight.
I am Murloc!
As has been said (over and over) already, a ressurection in RP should be quite hard to carry out, and should involve risks for atleast the person brought back, and very exhausting for the ressurector.